cory bethrant cornell presentation

Polymer Brush Data Processor

CORY BETHRANTAUGUST 12ND, 2016

DR. CHRISTOPHER OBERWEI-LIANG CHEN

Cornell University 2016

Introduction

What is a polymer brush?◦ Polymers with one end tethering to the surface.

Properties◦ Ordered structure – due to close proximity◦ Bonds are under tension


Polymer Brushes

With Charges, it could combine advantages of normal polyelectrolytes.◦ Anti-fouling ◦ Anti-microbial◦ Facilitate transportation

More stretching occurs due to charge◦ Stimuli-responsive material

Unfortunately it may be unstable◦ Additional Stretching causes the instability of the material

ACS Appl. Mater. Interfaces 2013, 5, 1400−1407

Kimberly Simancas, “Entropic death of polyelectrolyte brushes: chain stretching, bond scission and

surfactant complexation”, Ph.D. Thesis, University of Freiburg, IMTEK, Freiburg im Breisgau, July 2011.


4

Patterned CYTOP by photolithography

Hydroflouroether Lift-off

Patterned brush After HFE lift-off Patterned brush After Toluene wash and bath overnight

Creation of Bottom Up Template

Polymerization

Use toluene wash to remove free PMMA


CYTOP Film Thickness

(in nm)

RPM in spin cycle


Illustration of spin coating process

Surface Electron Microscopy Images of CYTOP Template

Sample: WC004Line: 500nm

Sample: WC014_2Line: 500nm


Patterned CYTOP

Atomic Force Microscopy

An Atomic Force Microscope operates using touch similar to a person feeling for a light switch in the dark.

2-D View of 3um Line

3-D View of 3um Line


Depicts How AFM Operates

The Problem?

Processing AFM Data takes a substantial amount of time.◦ 17 Lines Scanned = 1 Day of Data Processing◦ 5 Lines Scanned = 7 Hours

Human Error Likely Monotonous Requires Several Programs and Operations


Algorithm

◦ Determines the Slope of Each Dataset◦ Determines the First and Second Derivative of Dataset

◦ Using Numerical Approximation◦ Flag Whether the Slope is Positive or Negative◦ Saves Data Chunks of 5◦ Finds Left Border of Pattern Line Based off Sensitivity

◦ Once border is reached, a scan is performed in the left direction to locate the beginning of the left border.

◦ Finds Right Border of Pattern Line Based off Sensitivity◦ Once border is reached, a scan is performed in the right direction to

locate the end of the right border.◦ Baseline is average height of two borders◦ Height is calculated by subtracting baseline from max◦ Width is calculated by subtracting the right border values from the left◦ If error is recognized, scan is repeated with a decreasing sensitivity

number◦ Integral, Height and Width is Calculated

Demonstrates Program Accuracy


Source Code, Output

https://github.com/corysmart/Polymer-Brush-Data-Processor Output.csv


Data Processor Results


Error Bars Denote Standard Deviation

Results

What was learned:oHow to operate the AFMoHow to operate the SEMoData ProcessingoResearch SkillsWhat was accomplished:oSuccessful Creation of C++ Data ProcessoroSuccessful Collection of AFM DataoOber Group Website Redesign


Screenshot of Website

Acknowledgments•Prof. Ober

•Malcolm Thomas

•Steve Kriske

•Dr. Darren Dale

•Wei-Liang / Matthias Menzel

•Ober Lab


(DMR-1460428 and DMR-1120296) (DMR-1205608)

Me, Matthias and Wei-Liang Ober Lab Group

cory bethrant cornell presentation

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